Modern consumer and industrial packaging often includes reinforcing tapes or tear tapes as part of their construction. Various tape dispensers have been devised to dispense such tapes into corrugator and packaging equipment. However, all have certain drawbacks.
One of the principal drawbacks of the prior art systems is in their techniques for changing from one spool of tape to another when the first spool becomes depleted. Many systems require that the packaging line be halted while a new spool of tape is installed and threaded through the appropriate tape guides. This interruption is intolerable in complex packaging lines which rely, for their cost effectiveness, on continuous, uninterrupted operation.
To partially alleviate the interruption problem, some tape dispensing systems rely on a human operator to stand at the ready and manually splice the tapes together. The operator loops the leading end of a replacement spool of tape about the free running tape on the first spool. When the first spool is nearly depleted, the corrugator or packaging equipment is slowed to about one third of its normal speed and the operator cinches the loop onto the free running tape to form a splice knot. At the same instant he manually spins the second spool to overcome its static inertia so that the machine can draw tape therefrom.
This approach, although an improvement, has several problems. One is that it requires a skilled operator to monitor the tape spools and be ready to tie the splicing knot at the critical instant. Another problem is that it requires the packaging equipment be slowed from its usual speed. Still another problem is that, even if the splice is successfully made (and often it is not), the operator's manual acceleration of the second spool may not be sufficient to prevent the tape from breaking when the packaging line suddenly starts pulling several hundred of feet of tape per minute from the spool. A tape break, of course, requires that the packaging line be stopped, the very problem that was sought to be avoided. Yet another problem is that some slack may be momentarily introduced into the second tape by the operator's manual spinning of the spool. This slack permits the tape to change its orientation and may result, for example, in an adhesive tape being applied to the packaging wrong side down.
Accordingly, a need remains for an improved technique for splicing from one spool of tape to another in an automatic packaging line so that the packing line can reliably operator without interruption.
A further need remains for an improved system for controlling the tension and orientation of the tapes during a splicing operation so that the spliced tape is not broken nor applied with the wrong orientation.
It is the object of the present invention to fulfill these and other needs.
According to one embodiment of the present invention, a spool of tape is provided with end elements that cooperate with end elements on the next spool of tape to make the tapes self splicing. One tape, for example, can be provided near its trailing end with a pin extending thereacross. The second tape can be provided at its leading end with a loop sized so that the pin cannot pass therethrough. When the pin engages the loop, the tapes become linked, causing the trailing end of the first tape to pull the leading end of the second tape into the packaging equipment.
The second spool of tape may be stationary when the splice is made. To prevent the tape from breaking under the strain of instantaneous acceleration, the tape path is provided with a movable roller guide. In one embodiment, this roller guide moves against the force of a spring and acts to shorten the tape path when the tension in the tape increases. The shortened tape path provides the packaging equipment with the tape it needs without requiring the second spool to contemporaneously dispense a corresponding length. As the new spool of tape comes up to speed, the movable roller returns under the influence of the spring to its initial position. An active brake assembly prevents the spool from unduly accelerating in response to this spring-driven lengthening of the tape path by the movable roller.
The foregoing and additional objects, features and advantages of the present invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.